Conventional mass spectrometry is a technique for converting molecules into ions and then separating the ions according to mass/charge ratios. The ions are accelerated by a strong electrostatic field and, in a time-of-flight spectrometer, ions of different mass/charge ratio are separated by the difference in time they require to travel over an identical path from the ion source to a detector electrode which are situated at opposite ends of an evacuated tube.
In some situations, it is desirable to measure the mass and/or the charge of particles which are not readily ionized. In addition, it may be desirable to measure the particle's natural or acquired charge without altering it by ionization. For instance, it is desirable to know the electrostatic charge and mass of toner particles used in xerography. This is the case because use of toner particles of a size and/or charge not in accord with specifications has a detrimental effect on the quality of copies produced by xerographic copying.
It is an object of the present invention to provide a novel method for measuring the mass and/or charge of charged particles.
It is a further object to provide such a method which can be used to measure the mass of charged particles which are not necessarily ionic in nature.
An additional object is to provide such a method whereby the magnitude of the particle's charge and its mass can be measured in a single operation.